It is known within the art to lighten and highlight hair with a peroxygen compound such as hydrogen peroxide. But, compositions for lightening and highlighting the hair have not been included in shampoos, since peroxygen compounds like hydrogen peroxide, are not stable in shampoos. An object of the present invention, is to provide shampoos which contain stable peroxygen compounds and thus can be used as hair lighteners and highlighters as well as shampoos.
Current products on the market for lightening hair come in two forms. The first is a spray leave-on peroxide solution. This product is used occasionally when the hair will be exposed to sunlight after application. Examples of such products include SUPER SUN-IN, SUPER WITH LEMON SUN-IN, and GRADUAL SUN-IN FOR MEN. SUPER SUN-IN has about 1.9% hydrogen peroxide at a pH of about 4.0. SUPER WITH LEMON SUN-IN has about 3.7% hydrogen peroxide at a pH of about 4.0. And GRADUAL SUN-IN FOR MEN has about 3.7% hydrogen peroxide at a pH of about 3.
The second product for lightening hair is a system which has two components: a bleaching component such as hydrogen peroxide and another component which is a bleach oil.
It is known to prepare an unstable composition by combining a bleach with a shampoo and immediately thereafter applying the resulting composition to the hair. This is usually done in a hair salon and will result in the immediate lightening of the hair. By contrast, stable shampoo compositions which gradually lighten and highlight the hair and which can easily be used at home are provided by the present invention.
Rieger, Surfactants in Cosmetics, at page 271, notes that shampoo formulations based on alpha-olefin sulfonates have exhibited excellent stability over a wide pH range and specifically at low pH's have demonstrated excellent hydrolytic stability as compared to shampoos employing alkyl and alkyl ether sulfates as the surfactants, which are completely hydrolyzed at pH 2 after 3 months at 55.degree. C.
Harry's Cosmetology, seventh edition, indicates at page 433 that alpha-olefin sulfonates have excellent stability which should provide a broad range of use particularly for building shampoos of low pH. However, Harry's Cosmetology at page 459 suggests that low pH's for shampoos are between 5 and 7. No mention is made of shampoos having a pH of lower than 5. Moreover, no mention is made of incorporating hydrogen peroxide into a shampoo and then shampooing over a number of days to gradually achieve the hair lightening and hair highlighting desired.
Stache, Anionic Surfactants at page 520, notes that disodium lauryl sulfosuccinate DLAS which is a surfactant commonly used in shampoos, dramatically degrades at pH 5 in less than 8 weeks.